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More or less like last year, I’ve taken most of the films that IMDb counts as 2012 releases and multiplied their IMDb Bayesian average rating times their Rotten Tomatoes critic percentages. Excluded were films with fewer than 2000 ratings, films with fewer than 20 critic reviews, and all documentaries. And so, here are the top ~36 films–all that scored over 6.0:

I played around with IMDB and Rotten Tomatoes scores for all films of 2011 to arrive, subjectively, at a reasonable formula for combining the two to make one list of the most highly-rated films of 2011: just multiply the unweighted IMDB score times the RT score. That allows newer / smaller films to enjoy the ratings IMDB users actually gave them while using RT to more heavily weight the field. The films that make up the top 20 don’t change much, though, whatever formula you use.

IMDb provides text file dumps of most of their public data. Below are this year’s films to date, ranked by the weighted IMDb score. I’ve included the current Rotten Tomatoes score for each.

Computing the correlation coefficient (r) for the raw, unweighted IMDb score vs. the Rotten Tomatoes score, I find it’s a .7. It goes down to .67 for weighted IMDb scores vs. Rotten Tomatoes, and that’s a weak correlation (r^2 = 0.45), indicating Rotten Tomatoes scores are not generally great predictors of what IMDb users will think and vice versa.

But if we consider only IMDb’s top 20 films for this year, the correlation improves greatly: r = 0.83; r^2 = 0.69. That’s a fairly strong correlation. Apparently, when IMDb users really like a film, Rotten Tomatoes critics do too. It’s the unpopular films that are a bit murkier.

Eyeballing the discrepancies at the lower end, it looks like Rotten Tomatoes may be a slightly better source for a neutral viewer trying to prioritize their movie choices. Both sources promote major franchises (Harry Potter 7.5, Fast 5, X-Men, etc.) as well as smaller, quieter films, but Rotten Tomatoes is usually more discriminating. IMDb users often give average ratings to films hated on Rotten Tomatoes (Transformers 3, Cars 2, etc.), but they never really love a film not also loved on Rotten Tomatoes. And the only film unpopular on IMDb that Rotten Tomatoes rates above 70% is Cedar Rapids. Where Rotten Tomatoes really goes wrong, though, is giving a “fresh” rating to films in the 60-69% positive range–those wind up all over the map in the IMDb ratings.

Verdict: to pick a current movie, just use Rotten Tomatoes and common sense. Focus on movies with lots of reviews that score 80%+ overall, and try not to waste time on anything that scores below 70% unless you feel pretty sure going in that it’s the perfect film for the occasion, in which case you may as well not consider any ratings at all.